; born in Cold Spring, N. Y.
, Jan. 8, 1830; graduated at West Point
in 1850, entering the topographical engineers
, and was assistant Professor
of Mathematics at the Military Academy from 1859 to 1861.
He was made colonel of the 5th
New York Volunteers, August, 1861, and commanded a brigade in the campaign of 1862.
In September he was promoted brigadier-general.
He engaged in the battles of Manassas
(or second Bull Run
, and Fredericksburg
After Feb. 4, 1863, he was chief of topographical engineers of the Army of the Potomac.
He was engaged in the battles of Chancellorsville
(where he was wounded), and in the combats at Auburn
and Bristow's Station.
In March, 1864, he was placed in command of the 5th Army Corps, which post he held until April. 1865, in the campaign against Richmond
, having been made major-general of
volunteers in May, 1863.
In that campaign he was exceedingly active and efficient, from the battle of the Wilderness
to the battle of Five Forks
In March, 1865, he was brevetted major-general, United States army.
He was the author of Explorations in the Dakota country
; Preliminary report of explorations in Nebraska and Dakota in the years 1855–
;57; and An account of the 5th army Corps at the battle of five Forks
He died in Newport, R. I.
, Aug. 8, 1882.
A memorial statue of him was erected on Little Round Top
, in 1888.